Vitamin D is a fat-soluble prohormone that can be synthesized from initial provitamin D upon UV radiation (typically sun exposure).
However, biological activity of ultraviolet (UV) radiation can produce both positive (synthesis of vitamin D) and negative effects (erythema and skin aging, immune suppression, etc.).
Therefore, monitoring of acquired UV doses of ultraviolet radiation is desirable but can be challenging. In particular, detection in situ of UV doses of ultraviolet radiation, and/or detection of the vitamin-D-synthetic ability of UV radiation, can be challenging although the synthesis of vitamin D3 in human skin is an important positive effect of ultraviolet irradiation.